# -*- coding: UTF-8 -*-
 
def reduceNum(n):
    print('{} = '.format(n))
    if not isinstance(n, int) or n <= 0 :
        print('请输入一个正确的数字 !')
        exit(0)
    elif n in [1] :
        print('{}'.format(n))
    while n not in [1] : # 循环保证递归
        for index in range(2, n + 1) :
            if n % index == 0:
                n //= index # n 等于 n/index
                if n == 1: 
                    print(index) 
                else : # index 一定是素数
                    print('{} *'.format(index))
                break
reduceNum(90)
reduceNum(100)